
Variable-Angle Spectroscopic
Ellipsometry
(VASE)*
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In variable-angle spectroscopic ellipsometry (VASE), polarized light strikes a sur-
face
and the polarization of the reflected light is analyzed using a second polarizer.
The light beam is highly collimated and monochromatic, and is incident on the
material at an oblique angle. For each angle of incidence and wavelength, the
reflected light intensity is measured as a function of polarization angle, allowing the
important ellipsometric parameter to be determined. An optimum set of angle of
incidence and wavelength combinations is used to maximize measurement sensi-
tivity
and information obtained ...